Dev environment

[magec]

Hi!

I don't know how you normally develop in PgCat, but I found it a bit cumbersome when I had to debug a ruby test that was failing. Running the entire test suite using the tests/docker docker-compose file is simple, but when you encounter an issue, fixing it is not as easy as it could be, mainly because:

• PgCat id compiled from scratch every time you run the tests
• Postgres dbs are also set up every run
• Ruby gems are also downloaded
• There is a chicken egg issue in the docker-compose because postgres dbs need to use the main network, so if you want to leave postgres containers running and rerun main to test changes, it won't work most of the times.

I understand that those heavily developing in this project have all these things set up in their own boxes, but I did want to have a development environment close enough to the test one so I can debug issues easier.

This PR adds a simple dev environment that works by running:

./dev/script/console

This leads you to a container similar with what is used in CI, but ENV vars configured to save build artifacts and ruby gems into dev/cache directory, so removing this container and running it again won't delete those files, making it faster to do test driven development. As the cache directory is inside dev it does not interfere with what you have outside.

A run example would be like:

In the end, this change is just a new docker-compose file and some bash configuration so the user running inside the container shared UID:GID from that running in the host, also, the container has strace, ngrep, psql and some networking tools to make it easier debugging.

Using it, I actually spotted the bug I was hitting in like minutes, instead of the 3 hours wasted before.

[levkk]

This is really great, thank you for building this!